android播放器实现歌词显示功能

网上android播放器虽然挺多，感觉提供的歌词显示功能比较死板，要么搜索给的条件死死的，要么放置sdcard内部的歌词格式需要统一，应该提供类似文件夹浏览的功能。^_^，不过在这之前先搞定歌词的现实界面：

播放器的歌词界面实现以下几个功能

• 根据歌曲的播放进度自下而上滚动；
• 提供上下拖动调整歌曲进度的功能；
• 突出显示当前进度的歌词段，并保证该歌词段处于布局中心
  

不多说了直接贴代码，首先开启一个线程每隔一段时间往view中送入一串字符

Java代码

import android.os.Bundle; 
import android.os.Handler; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
 
public class TextAlign extends GraphicsActivity implements OnClickListener { 
 
  private SampleView mView; 
 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    // Animation in = AnimationUtils.loadAnimation(this, R.anim.push_up_in); 
 
    // mView.setAnimation(in); 
    setContentView(R.layout.main); 
    mView =(SampleView) findViewById(R.id.text01); 
 
    Button bt = (Button) findViewById(R.id.Button01); 
    bt.setOnClickListener(this); 
     
    new Thread(new UIUpdateThread()).start(); 
 
  } 
 
  class UIUpdateThread implements Runnable { 
    long time = 40000; 
 
    long sleeptime = 100; 
    public void run() { 
      try { 
        while (time < 200000) { 
          Thread.sleep(sleeptime); 
          mView.updateIndex(time);//.index = mLyric.getNowSentenceIndex(time); 
//         Log.v("UIThread", mView.index + ":" + time); 
          time += sleeptime; 
          mHandler.post(mUpdateResults); 
        } 
      } catch (InterruptedException e) { 
        e.printStackTrace(); 
      } 
    } 
  } 
  Handler mHandler = new Handler(); 
  Runnable mUpdateResults = new Runnable() { 
    public void run() { 
      mView.invalidate(); // 更新视图 
    } 
  }; 
 
  @Override 
  public void onClick(View v) { 
    mView.mTouchHistoryY -=30; 
    mHandler.post(mUpdateResults); 
  } 
} 

     这里将时间送到SampleView中，该类对此时间进行加工得到一系列list（该list是动态生成的），从而根据时间的推移递增的得到一系列的字串。这个过程模拟了歌词的显示过程

      接下来的SampleView继承了TextView并重载了onDraw方法.注意，这里只给了个sample，里面歌词怎么生成的见YOYOPlayer。这里就不给代码了

Java代码

import java.io.File; 
import java.util.List; 
 
import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.Path; 
import android.graphics.Typeface; 
import android.util.AttributeSet; 
import android.util.Log; 
import android.view.MotionEvent; 
import android.widget.TextView; 
import android.widget.Toast; 
 
import com.android.lyric.Lyric; 
import com.android.lyric.PlayListItem; 
import com.android.lyric.Sentence; 
 
public class SampleView extends TextView { 
    private Paint mPaint; 
    private float mX; 
    private static Lyric mLyric; 
 
    private Path mPath; 
    private Paint mPathPaint; 
    public String test = "test"; 
    public int index = 0; 
    private List<Sentence> list; 
 
    private float mTouchStartY; 
    private float mTouchCurrY; 
    public float mTouchHistoryY; 
 
    private int mY; 
    private long currentTime; 
    private long currentDunringTime; 
    private long sentenctTime; 
    private float middleY; 
    private String middleContent="Empty"; 
    private static final int DY = 30; 
 
    private static void makePath(Path p) { 
      p.moveTo(10, 0); 
      p.cubicTo(100, -50, 200, 50, 300, 0); 
    } 
 
 
    public SampleView(Context context) { 
      super(context); 
      init(); 
    } 
    public SampleView(Context context,AttributeSet attr) { 
      super(context,attr); 
      init(); 
    } 
    public SampleView(Context context,AttributeSet attr,int i) { 
      super(context,attr,i); 
      init(); 
    } 
 
    private void init() { 
      setFocusable(true); 
      PlayListItem pli = new PlayListItem("", "", 1000L, true); 
      mLyric = new Lyric(new File("/sdcard/M0005044007.lrc"), pli); 
 
      list = mLyric.list; 
      mPaint = new Paint(); 
      mPaint.setAntiAlias(true); 
      mPaint.setTextSize(20); 
      mPaint.setTypeface(Typeface.SERIF); 
 
 
      mPath = new Path(); 
      makePath(mPath); 
 
      mPathPaint = new Paint(); 
      mPathPaint.setAntiAlias(true); 
      mPathPaint.setColor(0x800000FF); 
      mPathPaint.setStyle(Paint.Style.STROKE); 
    } 
 
     
    @Override 
    protected void onDraw(Canvas canvas) { 
      super.onDraw(canvas); 
 
      canvas.drawColor(Color.WHITE); 
 
      Paint p = mPaint; 
      float x = mX; 
      float plus =currentDunringTime==0?index*30: index*30 +(((float)currentTime - (float)sentenctTime)/(float)currentDunringTime)*(float)30; 
      float y = mY- plus+mTouchCurrY - mTouchStartY+mTouchHistoryY; 
         
      canvas.translate(0,y); 
 
      for (int i = 0; i < index; i++) { 
        String text = list.get(i).getContent(); 
        if((y+i*30)<=middleY&&(y+i*30+30)>=middleY) 
          middleContent = text; 
        p.setTextAlign(Paint.Align.CENTER); 
        canvas.drawText(text, x, 0, p); 
        // mY- mY/lines*(index - i) 
        canvas.translate(0, DY); 
      } 
    } 
 
 
    @Override 
    protected void onSizeChanged(int w, int h, int ow, int oh) { 
      super.onSizeChanged(w, h, ow, oh); 
      mX = w * 0.5f; // remember the center of the screen 
      mY = h; 
      middleY = h*0.5f; 
    } 
 
    @Override 
    public boolean onTouchEvent(MotionEvent event) { 
      float y = event.getY(); 
 
      switch (event.getAction()) { 
      case MotionEvent.ACTION_DOWN: 
        mTouchHistoryY += mTouchCurrY - mTouchStartY; 
        mTouchStartY =mTouchCurrY= y; 
        invalidate(); 
        break; 
      case MotionEvent.ACTION_MOVE: 
        mTouchCurrY = y; 
        invalidate(); 
        break; 
      case MotionEvent.ACTION_UP: 
        Log.v("Lyric content", middleContent.length()+""); 
        CharSequence chars = new CharSequence(){ 
 
          @Override 
          public char charAt(int index) { 
            // TODO Auto-generated method stub 
            return middleContent.charAt(index); 
          } 
 
          @Override 
          public int length() { 
            // TODO Auto-generated method stub 
            return middleContent.length(); 
          } 
 
          @Override 
          public CharSequence subSequence(int start, int end) { 
            // TODO Auto-generated method stub 
            return middleContent.subSequence(start, end); 
          } 
          @Override 
          public String toString(){ 
            return middleContent; 
          } 
        }; 
        Toast toast = Toast.makeText(SampleView.this.getContext(),chars, 1000); 
        toast.show(); 
        invalidate(); 
        break; 
      } 
      return true; 
    } 
 
 
    public void updateIndex(long time) { 
      this.currentTime = time; 
      index = mLyric.getNowSentenceIndex(time); 
      Sentence sen = list.get(index); 
      currentDunringTime = sen.getDuring(); 
      sentenctTime = sen.getFromTime(); 
    } 
  } 

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持自由互联。